From 5093c5872be3a041917828b2b53e9f981d754768 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Mon, 6 Apr 2020 20:03:59 -0700 Subject: [PATCH] mm/vma: append unlikely() while testing VMA access permissions It is unlikely that an inaccessible VMA without required permission flags will get a page fault. Hence lets just append unlikely() directive to such checks in order to improve performance while also standardizing it across various platforms. Signed-off-by: Anshuman Khandual Signed-off-by: Andrew Morton Reviewed-by: Andrew Morton Cc: Guo Ren Cc: Geert Uytterhoeven Cc: Ralf Baechle Cc: Paul Burton Cc: Mike Rapoport Link: http://lkml.kernel.org/r/1582525304-32113-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds --- arch/csky/mm/fault.c | 2 +- arch/m68k/mm/fault.c | 2 +- arch/mips/mm/fault.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/csky/mm/fault.c b/arch/csky/mm/fault.c index a6e8230b6fbf..4e6dc68f3258 100644 --- a/arch/csky/mm/fault.c +++ b/arch/csky/mm/fault.c @@ -141,7 +141,7 @@ good_area: if (!(vma->vm_flags & VM_WRITE)) goto bad_area; } else { - if (!vma_is_accessible(vma)) + if (unlikely(!vma_is_accessible(vma))) goto bad_area; } diff --git a/arch/m68k/mm/fault.c b/arch/m68k/mm/fault.c index 0c4a21a685d5..3bfb5c8ac3c7 100644 --- a/arch/m68k/mm/fault.c +++ b/arch/m68k/mm/fault.c @@ -125,7 +125,7 @@ good_area: case 1: /* read, present */ goto acc_err; case 0: /* read, not present */ - if (!vma_is_accessible(vma)) + if (unlikely(!vma_is_accessible(vma))) goto acc_err; } diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c index fb048ba2b91d..f8d62cd83b36 100644 --- a/arch/mips/mm/fault.c +++ b/arch/mips/mm/fault.c @@ -142,7 +142,7 @@ good_area: goto bad_area; } } else { - if (!vma_is_accessible(vma)) + if (unlikely(!vma_is_accessible(vma))) goto bad_area; } }